


Burning Together

by orphan_account



Category: Undertale, Undertale (Video Game)
Genre: ;3c, AU, Accidental Voyeurism, Anal, Anal Fingering, Anal Sex, Brotherly Love, Cinnamon Roll, Crossovers & Fandom Fusions, Cumshot, Daddy Kink, Dom/sub, Dominant, Exhibitionism, Fluff, Fluff and Smut, Fontcest, Fusion, Gloves, Incest, Kissing, Light Masochism, Light Sadism, M/M, Maid Costume, Male Solo, Masturbation, NYEHEHEHEHEHEHEHHEEHHEHE, Penetration, Rough Sex, SINnamon roll, Sensitive bones, Sexual Tension, Sibling Incest, Smut, Soul Sex, Submissive, THEN IT BURNS INTO SIN, THIS FIC STARTS AS FLUFF, TOO MANY TAGS GO ME, Teasing, Tentacle Bondage, Tentacle Dick, Tentacles, Underswap AU, Voyeurism, bonecest, brushing, ectodong, ectotongue, heat - Freeform, in heat, romantic situation, sexual situation, sin - Freeform, temptaion, toothbrush fetish
Language: English
Status: In-Progress
Published: 2016-01-06
Updated: 2016-02-04
Packaged: 2018-05-12 05:02:21
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 13,679
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5653369
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: <blockquote class="userstuff">
              <p>Underswap Sans and Papyrus going through all sorts of sexual scenarios. But when their passion burns intensely enough, through their heat they form something even greater.</p>
            </blockquote>





	1. Lighting the Fire

**Author's Note:**

> Hi there! This is my first multi-chaptered fanfics and to celebrate 1000 Followers on Tumblr (I run an undertail fontcest sin blog so if you can check it out, it's Sansapapyrus). For those of you who haven't read 'Facing the Heat' written by a friend of mine, please do, their work served as inspiration for my fic although I added some extra spice to mine in some fun ways.
> 
> This fan-fiction takes place in the underswap universe, which is where most of the characters have swapped roles (this is not my AU). Which means that Sans is more like Papyrus and Papyrus is more like Sans. They've also had an age swap in this AU. In addition, later on the work, the two brothers will fuse into the great COMIC PAPYRUS, who acts as one body but both parts of Sans and Papyrus have their opportunities to think within their head.
> 
> Some general notes about the underswap AU (most of them fandom approved) and Comic Papyrus (CP) are:
> 
> -Sans is younger and still innocent, although he does have sinnamon roll like tendencies. He wears a blue neckerchief and bright white and blue clothes, similar to how Undertale Papyrus wears his clothes.  
> -Papyrus is the older brother, dressing casually in black shorts, sneakers, and an orange hoodie with a black tank underneath. He smokes, although it might just be to look cool.  
> -Papyrus is easily unsettled by his brother's 'nativity', which lets Sans easily toy with Papyrus, making him squirm in desire for him  
> -Sans calls Papyrus 'Papy' when in heat, Papyrus can barely even utter his brother's name.  
> -Papyrus has an orange dong, Sans has a blue one. There is a considerable size difference >:3  
> -Papyrus' orange ectodong feels warm to the touch, emanating steam and glowing brighter with growing arousal  
> -Sans' on the other hand feels cold and glows a vivid light blue  
> -Both skeletons have souls of their respective colours within their ribcages, which can be grabbed and squeezed, it's essentially like a g-spot but more tangible  
> -Papyrus likes honey: sticky, gooey and thick  
> -Papyrus is an ass man. He just is.  
> -Alphys is now head of the royal guard, Undyne is the royal scientist.  
> -Comic Papyrus when fused experiences heightened sensations  
> -Comic Papyrus' ectodong is a mixture of Sans' and Papyrus', a mixture of flowing orange and blue, almost electric in feeling and being a well sized appendage.  
> Most of the readers should know the characters well enough so I don't think I need to go on much more. 
> 
> L E T U S B E G I N . . .

Snowflakes: graceful and crystalline, with sharpened edges. Papyrus drearily raised his head from his afternoon nap and looked up towards the grey, clouded sky, a drifting snowflake sauntered into his eye socket, sending a light shiver along his body. The corndog stand was empty, again. A bottle of honey sat on the counter, usually for customers to dress their deep fried dogs with, but today it remained untouched. An orange bead of honey sat on top of the screw-cap lid. Papyrus lazily reached for it, pressing his index finger into the viscous fluid and then bringing it to his mouth. His thin, slippery orange tongue wrapped its way around his finger pulling it into his maw, he sucked it clean off of his finger before returning back to his work. Or lack thereof.

Minutes passed as more snowflakes settled themselves on the countertop, they carried an air of innocence with the way they fell, haphazardly but casually aware of the path they wanted to follow. Papyrus withdrew his packet of cigarettes from his pocket, suspending them mid-air using his magic as his left eye began to illuminate. He rummaged through his other pockets for his lighter whilst the packet shook open and slid out a cigarette. Time passed slowly as puffs of smoke filled the winter air. Papyrus watched as the sky cleared above, the Sun made its minimal reappearance, but it was enough to begin to melt the light snow that had settled.

Sans was out training with Alphys, the young royal guard in training wasn’t much for combat, but with a keen eye for detail, he could easily take down even the largest of foes with his cunning trickery. He was naturally dextrous with small and calculated fingers. He knitted the pockets onto Papyrus’ hoodie with the tiniest thread and needle and was an expert with small robotics, courtesy of Undyne. It didn’t help that he was also cute. Round faced with wide, deep sky-blue eyes, Sans could infatuate anyone if he put his soul into it, even Papyrus. His endearing nature could distract a foe, feigning a childlike innocence, before setting in for the kill. Undyne described him as a yandere in training. Papyrus didn’t know if he liked that label.

* * *

 

It was on one particular day in training that sparked something odd. Sans was to perform an ‘assassination’ of a ‘victim’ with a rubber knife. Alphys decided that in order to make things interesting she would make Papyrus his target, a sibling near and dear; someone beloved. Undyne held a clipboard in observation, the head royal guard and scientist respectively were excellent battle strategists: Undyne’s wit and careful prognosis of events through strict analysis and Alphy’s brute strength and crafty maniacal tactics meant that their royal army was one of the Underground’s finest.

“You did well in choosing Papyrus as Sans’ battle partner Alphys,” Undyne looked down at her notes, surveying the checklist of pros and cons she had collated, “Obviously their kin relation is going to make things tense…” She held back a chortle as to what she knowingly implied by the word ‘tense’.

“And, Papyrus has strong magic powers, telekinesis and teleportation. The size difference and Papyrus’ much more masculine physique would make him a much more yaoi opponent compared to Sans.” She froze up as the words slipped out. Alphys just looked back with a sly smirk and a soft jab to the shoulder. The two royal staff were fully aware of their own personal pairings.

“You were saying Undyne? We both now they’re bound for each other anyway. It’ll make the fight more interesting!” She burst out heartily as Undyne chuckled to herself. “You know what Alphys, just watch.” She returned the jab knocking her fist against her shoulder plate with a twang.

Papyrus stood up straight, in a semi-prepared battle stance, hands in pockets and feet spread comfortably in front and behind. The clouds had rolled in over the Sun, casting shade over Papyrus, concealing his conceited grin under his hoodie, a veil of darkness surrounding him. He had an air of cocky confidence in the way he held he shifted his weight to and fro onto either foot, he could easily handle Sans, his 4'8" statue was nothing to Papyrus' 6'4" skyscraper body. Papyrus’ eye glowed softly, squirming in the way it twitched and blazed in his socket, on the inside, he was afraid.

The two were to fight in a clearing in the forest, where now gentle sunlight filtered through the canopy in blades of gold. Undyne looked down at her notes in fear as rain began to drizzle in from above. The wind picked up too, swirling leaves of orange, brown, red and yellow around. Seeing both skeletons about to fight in the now wet and muddy conditions was to be mesmerising. The entire area was like a painting: two brothers to fight in a gentle storm, wind and leaves bewildering them as a light fog masks their expressions. Tension was running thick, burning like a fire within the two of them.

Sans stood forthright, posture straight and balanced; careful. His blue neckerchief was now over his mouth masking his expression. His eyes however, were in full view, blue irises glowing gently. His fingers were casting an ethereal smoke which dissipated in the autumn air illuminating the close-range fog the rain had brought along with it.

The scene was set, one brother had to die, lest the other be drowned in shame.

Alphys counted down from ten. The two brothers has locked eyes, forcing them to stare right into each other’s head.

10…

9…

8…

“(Think Papy, he’s little, don’t hurt him, god forbid you hurt him. Fuck, he’s staring at me with those eyes…)”

7…

6…

“(He’s not my brother, he’s my opponent. He might have the height and he might be strong, but God he could pin me down so easily…)”

5…

4…

3…

“(God this is too hard, I can’t, and I’m burning up. Papy…hold, yourself, together. My face is burning orange now, shit. SHIT! Sans can't see me like this! FUCK!)

2…

1…

“(He’s blushing!? Oh jeez…what’s he playing at!? I can’t let him distract me like this…as cute as he may look…GOD SANS FOCUS! WHY ARE YOU THINKING LIKE THIS!? ABOUT HIM!? This might be harder than I originally thought…)”

Alphys slammed her axe into the ground, shaking both Undyne and the trees, “GO!!!!!”

* * *

 

The familiar smell of minced beef was a sign that Sans was cooking Dinner tonight, tacos, his defining speciality. Papyrus was at the front door of their house, the roof and porch were covered in fresh snow during his walk home. He dropped his cigarette into the snow and gave the door a brushed knock, crushing it beneath his sneakers, revelling in the squelching noises it made beneath his broad foot. As its colour died out, orange embers vanishing as quickly as they revealed themselves, a small skeleton smiling brightly opened the door. He was donning the maid costume Toriel made for him, after being inspired by Muffet’s bakery, Sans took it upon himself to emulate her work ethic. Fortunately for Papyrus, even down to the minor details…

“Hey Papy, back from work I see.” His face was beaming, cheekbones a faint but brilliant blue. “I'm making tacos, I decided to use some of the spices Muffet gave me while I was out today. She said they’re some of her best!” Sans runs back to the kitchen, Papyrus eagerly following behind him watching the tassels of Sans’ white lace apron swing between his thighs. An array of steel pans and copper pots are simmering gently on the stove, one filled with a red sauce, another filled with fried ground beef. Nips of oil flash out of the pan as sans pours the red sauce onto the beef. He poured slowly, consistently, bending slightly at the knees to keep his stance correct.

Papyrus sat on the table watching his brother do his work, “You’re quite, articulated, aren't ya Sans?” The question distracted him slightly as Papyrus levitated a bottle of paprika and rolled it across the floor, a typical prank Sans hadn't picked up on. “I suppose you can say I am Papy, I pride myself in- oh wait!” Sans’ eyes follow the Paprika as it rolls under the table, and stops at the wall. Papyrus pre-meditatively stood up, “Oh don't worry I’ll get that Papy, the food’s ready anyway so I’ll just quickly turn off the heat…”

Papyrus giggled at the subtle irony of the phrase. “Okay, I’ll be here watching and waiting…” Sans knelt down to get the bottle as Papyrus got ready to roll another condiment in the opposite direction, it was a bottle of honey. As Sans began to bend over a lack of panties or underwear became apparent to Papyrus as he choked on the now dense air around him, this wasn't part of the plan!

“Sans, w-w-w…” Sans returns from underneath the table, a ginger smirk plastered across a placid and innocent façade. “Papy, what is it?” Sans walk past Papyrus and sits on his lap, legs placed Papyrus’ so he was facing away, his round head tucked under the older skeletons neck. “Your face has gone orange, hasn't it? You need something? Do you want me to give you anything Papy? I really want you to be happy with me.” Papyrus swallows nervously as Sans wriggles his hips slowly, grinding his tailbone through his shorts against his pelvis.

“S-s-s-s-Sans, under the table, there’s a bottle of honey, could you go get it? I-I think I’ll be in my room for a while…” Papyrus lifts Sans up and catches glimpse of something blue and dripping. “SANS I HAVE TO GO DO SOME SHIT!” Papyrus ran to his room, grabbing a nearby bucket along the way, the squeaking of sneakers against hardwood stairs being the last sound heard in the room before a slam and lock of his door. Papyrus hadn’t seen this side of Sans since the assassination lesson…

Now all that was left in the kitchen was Sans, and the honey. Sticky, gooey, thick, warm and golden honey.

 


	2. Heated Assassination

**Summary for the Chapter:**

> In a flashback to the original spark of their love, Sans must kill his brother in fake assassination to enter the royal guard. But tensions start to burn orange and blue as traditional offensive tactics evolve into risqué deception of the sinful variety.

Autumn leaves tumbled through the air, trees still trembling as the ground reverberated from the pounding of a heavy axe upon sodden soil. Sans and Papyrus still hadn't moved from their spots. The mud had begun to bury their shoes as the rain began to make their battle field a slippery mess of brown and green. The rain was pouring down heavily, fog had filled the area, casting everything in a light grey haze. Undyne and Alphys stood together beneath umbrellas, patiently awaiting to be enthralled by the display before them. Sans held the rubber knife firmly behind his back, the blade firmly clasped, twirling the khaki coloured blade.

The knife was military grade, with a serrated edge and a sharp back blade. Upon striking the target, it would leave a trail of orange ink and vibrate in the user’s hand alerting the assassin as well any onlookers that they scored a direct hit on their victim. Papyrus had tightened his hoodie, hiding his blushing face. Now only his glowing eyes were visible as well as the faint ethereal emissions his fingertips were giving off. There was something off about the way Papyrus was no longer shifting on his legs, perhaps it was fear, or if the sombre orange resonance in his pants had anything to do with it, sheer unbridled terror.

Sans pulled back, then launched forward in broad strides, bounding and splashing in the mud. He was so nimble on his feet. Papyrus straightened out his posture as he braced for his plan of retaliation. Sans jumped, using a touch of magic to elevate his body, he followed a fluid arc as he brought the knife crashing down into Papyrus’ skull, he closed his eyes as it landed, vibrating upon contact.

“You missed me there bro.” Sans pulled the knife out of the muddy orange ink pit he made in the mud, desperately searching for his target. Papyrus had vanished and reappeared behind him, leaving a vaporous trail of orange between his origin and return point. “You’re gonna have to try harder than that if you want to assassinate me…” He let out a chuckle, he needed to distance himself, he couldn't attack Sans head on, too risky. Sans turned around, his eyes carrying sane insanity, this wasn't Sans anymore, this was a cold-souled murderer.

He sent the knife dancing into the air, letting it spin until his magic took over and held it in the air, the sharp edge aimed at Papyrus' face, “You better start running Papy…” Papyrus bolted through the downpour, his hoodie completely drenched, clinging to his skeleton and sticky in the heat. “Stay vigilant Papyrus!” Alphys’ voice boomed from the right, they were watching in awe, “The little knucklehead has all of your powers, use that knowledge to your advantage!” The advice was duly noted and quickly realised as a horizontal blue bone materialised and swung towards his legs.

Papyrus jumped straight up, twisting in a 360 to poke his tongue out at Sans, “Missed me again bro…” But Sans was gone, he’d vanished. A sharp blow to the back of Papyrus head soon followed, what came next was a blur of rage and fear, which became, all too quickly, madness and terror.

The bone knocked his vertical body horizontally in a perfect right angle. Ebbs of blue magic contorted him to be flat, stomach face down. He was a metre off the ground staring at the mud as Sans ran beneath him sliding on his knees, his eyes were burning a bright blue as rain dripped across his face. “Get ready Papy.”

He threw the knife like a bullet past Papyrus’ skull before vanishing again. “YOU MISSED ME THERE SANS!” A bone struck Papyrus’ outstretched arm, the momentum turning him 180 to now face the black raining sky. Sans reappeared high in the air, he caught the knife, “Did I really miss you Papyrus?!” The magic around Papyrus faded as he fell into the mud and Sans came rocketing down for the kill. The last thing he saw was the perfect smirk on his own brother’s face. Sans saw a quivering, wet, terrorised target, eyes trembling, hands desperate to fight back. The knife shook again, and an explosion of orange ink sprayed outwards like blood.

“You’re too predictable Sans…you’ve done that twice now…'A Plus' on creativity for the setup, your  execution, however, was poor.” An audible cheer of excitement from Undyne squeaked from across the field as Sans continued his onslaught. Sans threw knife across the field like a javelin as Papyrus ducked, the knife bent upwards at a right angle from where Papyrus’ head was moments ago. “Let me guess Sans, it’s gonna come back dow--- WHA!?” Papyrus shot up into the air, following the knife, one long femur beneath each foot as he ascended into the air like a bottle rocket.

“Have a nice flight Papy!” The small skeleton chuckled to himself, giving him a wave goodbye. There was no escape for Papyrus though as more bones surrounded him in a floating cage. He tried vanishing, but he couldn't this time. “ _C’mon Pap, stop thinking about Sans, you just have to restrain him, then...kill him...maybe. Why does he have to be so fucking cute though!?”_ Papyrus kicked his foot upwards dragging the femur into the dropping knife kicking it away, shattering the bone in half with the force in his legs.

“He’s good Alphys, I mean really good!” Undyne was making more notes, her pen rapidly clicking between colours for each new observation. Alphys has her eyes on the battle, watching every step, skip and jump, “Which brother though Undyne? Sans takes his time formulating plans, he puts good force behind his movements, but he’s too predictable, a bit of a show off. Papyrus on the other hand is clever, a bit of bastard with his cocky smart talk if you ask me, but clever. He’s also strong, I don’t think he knows it, but he’s got a lot of strength.” Undyne cackled, “Imagine Sans walking in on Papyrus lifting weights, Papyrus would be drenched in sweat, no hoodie on. Sans would lose his shit so quickly he’d go ‘blue heaven’ in his pants within _seconds._ ” Alphys choked on the rain at her colleague’s accusation, she took a moment to breathe between heckled coughs, “Oh my God Undyne he so would.” They were bursting into tears at this point. They both knew there was something between those skeletons, they just had to wait for them to realise it too.

The two brothers looked as if they were fighting on a two-dimensional plane, bones swinging high and low, both skeletons vanishing into thin air, then reappearing in bursts of luminescence, their glowing trails the only feasible way to track them from point A to point B. Papyrus was burning orange, his while body now encased in the glow, he was visibly fatigued, now slouching during the brief moments in which Sans was recuperating. Sans was encased in vivid blue, this had never happened before, they were using a lot of magic. “Why won’t you just die Papyrus!?” Sans screamed across the battlefield as more leaves flew through the air, their flights cancelled as they were brought to the ground by the rain. “Just let me kill you!” Sans brought his neckerchief down from his face, a small blue tongue now revealing itself. It was dripping a light blue, luminescent fluid. Papyrus had an array of bones lined up behind him, ready to deflect, retaliate, or dispatch whatever offensive manoeuvre Sans had planned.

Sans held the knife out, dropping it flat into the mud, letting it sink into the soaked Earth. He slowly stepped through the rain, it was time for a new approach to the same problem. “Papy. I'm done fighting, you win. I don’t want to fight my big brother anymore. I can tell you don’t want to fight either, not like that glowing in your pants has anything to do with it…”

“ _WAIT WHAT THE_ _FUCK! How does he know? How **can** he know? He shouldn't know about **that** magic trick. I wanted to show him too. OH GOD!” _ Papyrus was shaking, completely out of breath, patience and stamina. His pants were glowing, most of his energy went to suppressing the heat. He couldn't let Sans know, but he did. Sans slowly got closer. His face was childlike, a weak smile, a small tongue in his mouth, tiny sharp fangs, those big blue eyes. He had a lamb’s eyes, they were pure, sinless; innocent and devoted. Alphys and Undyne had stopped their chatter. They were watching in screaming silence.

“Is…is the fight over Alphys? This means he’s failed right? I knew this was a bad idea Alphys…we shouldn't have made him fight his own brother…” Alphys was watching Sans amble towards Papyrus, watching his feet crawl through the mud. “Undyne, look at where he dropped the knife, do you notice anything slithering through the mud.” She grabbed the scientists’ glasses and cleaned the rain off of them, “Look in the mud, the space between his feet,”

“What about it Alphys? I can’t see it.”

“It’s glowing blue.”

“That sly little bitch.” Alphys gawked at the royal scientist, impressed by her new found abhorrent commentary.

“S-s-s-s-Sans…what are you doing?” Papyrus was scorching, his face and eyes and soul were all burning together in painful unison. “I want to stop fighting Papy, I can’t kill you. I love you too much. You never fought back, not once. You showed me mercy.” Sans crept up, his face glowing a gentle blue, he pulled his brother into a tight hug. He submerged his face into the space where his tummy would be, arms wrapping around his pelvis, the only place he could connect his hands comfortably for his short height.

Papyrus returned the hug, inelegantly keeping his hips bowed away from his brother’s chest. His glowing member was trying to make it’s move, Papyrus could feel its heat, It was burning intensely. “You feel warm Papy. Maybe you should take off your hoodie, the weather is nice and cool after all.” The words ricocheted within his skull, the internal pressure pushing him to shatter, or at least tear his shorts at the seams. “I'm good S-s-Sans, t-trust m-me. I'm perfectly f-fine.” Papyrus lifted off his hood, showing his sodden and blushing face and looking down towards Sans.

 _“Fuck… Papy. Just don’t look at his eyes. Just smile, and hug. No one has to know. The heat will pass, I just have to hold myself together.”_ Sans hugs a little tighter, shifting his weight uncomfortably, causing Papyrus to constantly shuffle on his feet. His sneakers slid around in the mud. He had to keep his balance up or he would topple.

“Hey Undyne, look at Papyrus, isn’t it funny how they’ve both got concealed weapons?”

“Alphys really!? That’s what you’re focusing on? You need to get your mind out of the gutter...” Both of them watched on, somewhat excited as the theatrical seduction moved onwards.

“Papy,” Sans moves his arms to lift off Papyrus’ jumper, “Let me help you out of that stuffy jumper Papy, you look so hot in there…”

Papyrus shook nervously as he lifted as arms to give Sans some leeway, his black tank top was all he had on, it clung to his ribcage and shoulders, the wet rain made it cling to him like plastic wrap. “Isn’t that better Papy?” Sans rubs his fingertips along Papyrus’ ribs, reaching up and leaning forward. “Sans what are you doing? Sans I’m gonna slip. S-S-SANS!!!”

Papyrus fell backwards into the mud, Sans landing face down on top of him. The two brothers were now awkwardly sitting in the wet sludge. “Sans! What is wrong with you!?” Sans looked up, doe eyed, loose tongue drooling as his small hands reached down towards his brother’s waistband. “Papy, I want to say sorry for trying to kill you. It’s the best I can do for you.” Papyrus looked down towards the large growing and glowing tent in his pants. Sans had never seen his cock before, at least he thought he hadn’t. “Sans!? Tell me what you’re doing?!” Sans looked up from his trance, blue irises glowing in two round rings, little fangs dripping from the rain, “Papy, I’ll tell you soon, just let me do this. Let Sans make you happy.”

Sans pulled his brother’s waistband up and dragged it towards him. “Papy you’re so big. I can’t even lift the waistband over your own dick.” Papyrus placed a shaking hand over his face, this couldn't be happening. “Sans please, not out here, not like this. Undyne and Alphys are watching...” Sans pulled the waistband over the head of Papyrus’ enormous cock, it bounced straight up,  it was rigid, leaking orange precum in the rain. It was glowing and smoking orange. “SANS PLEASE!” Sans wrapped his tiny fingers around only half of his brother’s thick girth, carefully stroking the hard cock’s shaft up and down lovingly, his fingers innocently exploring its entire length. Papyrus began to whimper in pleasure at his brother's gentle touch.

“Sans, w-w-why did you wait until now to do this?” Papyrus was tearing up, his entire body was glowing orange, his eyes, face, tongue, tears and erection all glowing even brighter. “I've waited years for you to notice me, and you approach me now? I love you Sans, I love your body, the way you look at me, the way you talk, y-y-your,” Papyrus stuttered as Sans finally looked back at him, not as a target, but as Papyrus, “your innocence…” Sans keeps stroking as he pulls Papyrus’ shorts down his legs. “Sans, what’s wrong with you? You’re not even listening to me anymore.” Papyrus lets out a muffled moan as a loud thunderclap screams from above.

“Papy, please, one more minute, I’ll explain later.” Sans places both of his hands around the head of the cock, his eyes are glowing fervently, his tongue slips down in the form of a thin tentacle, sliding its way down and around the shaft, stopping it the base to tighten itself. Orange precum and blue saliva mixed and dripped in the rain. “Sans…fuck…please…” Papyrus slammed his hips skywards, Sans’ hands sliding downward with his upward thrust, “Sans holy fuck! Where did you learn how to do this?”

Sans unwrapped his tongue and released his brother’s cock. He crawled further up his brother, making him lie flat in the mud, blue tentacles slithered out from behind Sans, wrapping around Papyrus’ arms. He was pinned in the mud, another thunderclap, even louder, even brighter, the sounds and colour and light all too vivid to even be real. He was on top of Papyrus, his tailbone pressing against the tip Papyrus’ member. Little hands used Papyrus' ribs as handholds as he climbed over the location Papyrus’ soul. It was glowing orange, the heart shaped organ being an indicator of pleasure. “Okay Papyrus, I’ll be honest with you, I wasn't expecting it have to come to this.”

“What do you mean by _this_ Sans?” Papyrus struggled and winced against the tentacles holding him down. He was face to face with the skeleton that just tried to kill him, the sky above was black. Another bolt of lightning danced across the sky, Sans’ face lit up, blue eyes staring down. “I didn't think that I could seduce you like this Papy. I knew you thought I was cute, I’ve seen you in your room, when you think you’re alone. Almost every day I check to see if you’re there, I listen to you climax, it sounds so rough. I hear you breathe my name to your pleasure.” Papyrus flushed orange again, he _was_ aware. He knew  _everything._

“You feel the same way then Sans. There’s no shame here? ” Papyrus felt a warm tear scroll down his cheek.

“None at all Papy.” The rain was dripping off of them both. “Oh, and Papy,” another thunderbolt lit up everything a final time, **“checkmate.”**

Sans rolled off Papyrus as the sound of tearing fabric ripped louder than everything else around them. The knife shot through Papyrus’ chest from below, coated in blue magic as orange ink sprayed over his ribcage and face, coming clean out the other side. He used Papyrus’ glowing soul as a reference point for the attack. He aroused him to make it glow a bright as possible. The knife slid underneath Papyrus though the mud, the hand job was just a minor diversion.

Alphys and Undyne stood is astonishment, jaws agape at the spectacle that just happened. “Undyne?! What actually was that?” Undyne was frantically taking notes and searching through them. “Sans pretended to be in heat. He played Papyrus like a fiddle, feigning arousal, distracting him, although it was also probably also an excuse to get up close and personal with him. Who wouldn't though?” Alphys let out a chuckle at the results of the battle and Undyne's sly words. “HEY SANS!!! YOU DID IT!!” CONGRATS BUD!!!”

Sans ran up to Alphys and Undyne and grabbed them both in a hug, Papyrus was still sitting in the pouring rain, he hastily returned his dick to his pants, the heat of arousal finally cindering away. Papyrus stood up and pulled his hoodie over his orange stained top. He huddled over to them before hugging Sans tightly, drops of rain phosphorescing blue and orange against happy tears of love. “Sans, you did it buddy.” Papyrus paused, collecting his thoughts, he had to finally ask what was on his mind. He leant in close to the younger skeleton,

“Sans, everything that just happened…was that…genuine? I mean, like, do you really want to make me happy? Did you really listen to my moans? Did you, I mean...do you love me?” Sans looked up, beaming, his face full of life. “Of course Papy. Every single moment was real,” He giggled and smirked, “It’s fun to take advantage of you. You squirm so easily.” Papyrus shivered and tried to ignore the comment as he picked up Sans in a tight love hug and gave his skull a gloved noogie.

“I love ya Sans. You’re part of the royal guard. You’re my incredible little bro.” Sans was laughing, smiling, it hadn’t been like this in a long time…

“Right back at you Papy.” Alphys and Undyne joined in on the group hug.

This was how it began.

* * *

 

Papyrus was locked in his room, crouched against the door in heat; burning.

 Sans knocked. Gently tapping the door. He knocked four times. Papyrus couldn't open the door. Not now.

It had been a month since the assassination lesson. Papyrus didn’t think he’d re-enter heat. Sans was acting odd too. Perhaps it was time he just accepted it. The smell of honey crept in through below the door.

“Papy. Come outside, I-I…” His voice trailed off, he was afraid of something, “I have something to show you.”

Papyrus stood up. He turned the knob. Sans was there…dripping…

_“Oh. My. Honey. Fuck.”_

**Notes for the Chapter:**

> Hooooooooooo golly gosh this chapter was fun to write.
> 
> This was the first fight scene I've written and to accompany it with some sexual tension and back dialogue was a challenge but I think I did my job well enough. Between envisioning Papyrus' thick dongle and Sans trying to wrap his tiny hands around his girth I hope you guys enjoy the lighter side of the sins. That's right, this chapter was a Holy Communion compared to what chapter 3 and 4 will have in store for you awesome peeps.
> 
> If you could leave your afterthoughts in the comments that would be awesome.
> 
> I hope you guys all enjoyed it ^_^


	3. Heat Displacement

**Summary for the Chapter:**

> DISPLACEMENT: the unconscious transfer of an intense emotion from one object or person to another.
> 
> Another flashback to Papyrus and Sans having a chat a few days after the assassination test. However, their conversation escalates as Sans becomes bedridden and experiences sleeping terrors.
> 
> Papyrus listens on in the burning darkness. The sparks between them begin to grind more and more. It all leads up to Sans finally talking about what's on his mind.
> 
> Papyrus teaches Sans some things, and we get another look at what's happening in the present. (I'm a tease...)

_"Hey Papy…What’s your favourite animal?”_ The taller skeleton looked at Sans’ inquisitive face, at the time it was simply just a naïve question. It had only been a few days after the assassination lesson.

Papyrus pondered for a moment before shooting back his answer. “Cats. Definitely cats. They’re soft, and fluffy…” He let out a low chuckle, “and I like it when they curl up on your lap and purr, they’re just so cute like that…” Sans giggled and made a small mewling noise as his brother went orange-faced at the adorable gesture.

“Thanks for letting me know bro.” Sans twiddled his thumbs, looking back and forth between his sibling and the television. An MTT brand advertisement was displaying some sort of new-fangled gadget for peeling vegetables, the robotic advertiser was grinning and raving on to their heart’s content. “Um…One more question Papy?” Sans clasped his hands nervously, occasionally adjusting his neckerchief and nonchalantly checking his skull for traces of nervousness in the form of sweat. Papyrus tore his head from the television once more, placing a hand on Sans’ leg before the smaller skeleton could say another word.

“Sans, you don’t need to ask permission to talk to me. If you have something on your mind, please just say it.” He picks Sans up and cuddles him in what became an upstanding hug. Their skulls clinked as the light from their blushing faces reflected off their white skulls. “You **_can trust_** me Sans. I promise. I could never get mad at someone as cute as you”

They swung around in their tight closed embrace, spinning faster and faster as Papyrus stepped across the room in what was an enchanted ballet. Papyrus jumped up into a slapdash pirouette and landed with some stylish grace before he broke into a sprint, hoisting the small skeleton onto his back. The room spun around them as Papyrus dashed even faster with Sans bouncing up and down, “So bro! What was the question?!” Papyrus has to yell at this point so Sans can hear him over his own eccentric laughter.

“Nyeehee…Papy…I can’t breathe…heheh…let’s s-s-sit down…please.”

Papyrus scampered to the top of the stairs holding his arms out like an airplane, Sans bouncing on his shoulders giddily. He looked down at the couch from above and took a few steps back, getting into a sprinter’s position. “Papy!? W-what are you doing!?” Sans clung onto Papyrus’ hoodie for dear life, wrapping his legs around his broad shoulders.

“Your bro’s gonna leap off and land on the couch. Think you can handle it? ” Papyrus turned to look at the now mortified Sans who was sweating bullets. All Sans saw, on the other hand, was his brothers smug-ass face, the corners off his mouth twisted upwards into an evidently devious smirk, which was withholding a maniacal chortle.

“PAPY W-W-WAIIIIIIIIIIIITTTTT!!!!!!!!” Too late. He’d jumped. Everything went into a slow motion blur as Sans pulled Papyrus’ hoodie down over his eyes, blinding him as they both entered panic. They flew as elegantly as one could while in their terrified state of screaming. Sans clung tightly to his brother, wrapping his arms around his ribs. Papyrus yelped unexpectedly at the pleasurable squeeze to his chest; blind and now also in a state of unforeseen arousal.

Sans squealed as orange magic enveloped him and Papyrus as they froze in the air, suspended above the couch like puppets. Papyrus pulled off his hoodie, returning vision to his now glowing eyes. They were burning orange, a wispy smoke dispersing into the air around them. Sans was still in shock, arms and legs splayed outwards, mouth agape, little fangs dripping in blue saliva from the adrenaline rush. His body was adrift in pseudo-space.

“What’s wrong Sans?” Papyrus was grinning, holding back uncontrollable mirth, “ _CAT_ got your tongue!?”

Sans looked at Papyrus with enraged cerulean eyes, his own brother had turned the original question against him, he had been **punned**. Sans puffed out his chest and folded his arms in a gesticulation of subtle anger, a façade for the indescribable rage within his small candid body. Sans surrounded himself in his blue magic, cancelling out his brother’s.

“OH MY TORIEL!!! PAPYRUS YOU WILL REGRET HAVING MADE THAT PUN!!!” Sans rocketed his airborne incandescent body at Papyrus, aiming again at his ribs. He grabbed Papyrus by the front of his hoodie as they plummeted as one mass downwards. Sans looked at Papyrus with fury, eyes locked together not having realised that there was now no magic suspending them mid-air like the marionettes they had made themselves into. His eyes softened to a wince as newfound fear replaced rage.

“Papyrus! Help me!!!”

Papyrus pulled him and Sans into a ball as they landed on the couch, the springs compressing and relaxing as it adjusted to the weight and impulse of the impact. Sans was clinging onto all he held dear as their bodies finally ended their long (and somewhat arduous) dramatic movement. Papyrus was breathing heavily as Sans collapsed into a panting heap on top of him, hands and fingers firmly pressing into his jumper. Their legs were overlapping one another. Papyrus’ eyes had stopped glowing.

Sans on the other hand was glowing brightly, his eyes were still in embers, his face was glazed in an azure blush, his soul was a deep ocean blue; faintly visible. His fingertips were casting off gentle wisps as he indiscreetly pulled his white shirt over his knees to sit in a ball on Papyrus’ pelvis.

“WHAT WAS THAT FOR PAPY!?”

Papyrus burst into laughter, “Sans you’re too cute,” he put on a mock cinnamon coated voice, “’what was that for Papy?’ you know exactly what that was for…” Papyrus sat up to face Sans and give him a light noogie, but the air hadn’t weakened, there was still an unresolved matter at hand.

“NO I DON’T PAPYRUS!” Sans sniffled as he tried to hold himself back, “I-I…I don’t understand Papy…” small droplets began to slide down his face, glimmering as they reflected blue light through them. Papyrus had gone too far. “I-I….don’t understand…” Sans’ eyes slowly glazed over as he lost focus on his brother.

“S-Sans?” Papyrus pulled the glowing ball in close, pulling him into a hug, “I-I didn’t mean to hurt you Sans.” Sans didn’t appear physically hurt. He placed the back of his hand against the younger’s head, he was warmer than usual. “Sans! Are you okay!?” Papyrus stood up and bolted, the small skeleton cradled in his arms, his eyes were closed, but his body was still glowing. Papyrus ran into Sans’ room and laid him down on the bottom bunk of his crane bed. He undid his neckerchief and pulled a chair next to his bed, he hadn’t done this for a while.

“Wait here little bro, I’ll be back soon. I promise.” Papyrus ran downstairs and grabbed some containers of food, his guitar and some books. He also grabbed the phone and began dialling a friend. The phone rang slowly, each electronic ring a shotgun bang in the door of his mind, ready to snap inwards in fear of the oncoming events.

“Good afternoon,Head Royal Scientist #003 Undyne speaking, please state your emergency.” Papyrus held the receiver uneasily, his hands were shaking and started clamming up, his voice was no better as he brought the microphone to his weak lips.

“U-UNDYNE!” He paused to calm himself, “It’s…Papyrus.” He waited for her response, every second was a punishing throb against his skull.

“Oh hey Pap! I, wasn’t expecting you to call on the Royal Medical Line, something wrong? Or did you lose your cell again?” She snorted to herself.

“Undyne, I think S-Sans is…sick…or worse…” the words couldn’t slide out of his mouth properly.

“Pap, let me guess. You think poor Sans is in heat.” She tried not to audibly smirk, she knew it wasn’t serious, this was one of the rare opportunities for her to chuckle meekly to herself, “Let me tell you straight Pap. Sans can’t be in heat, it’s only been a week since he last burnt his fuse. If anything, he’s just fatigued.” A static sigh of relief was heard over the phone from the hooded skeleton.

“Thank Toriel Undyne, I could barely handle Sans the first time he went into heat, and he was trying to kill me for fuck’s sake!” Papyrus let out a partially hysterical laugh as he reminisced, “You said he should be just fatigued right? That makes sense after all, we were playing a…uh…game before and he just passed out…I think I was too rough with him.”

“Papyrus you got to remember he’s not as…well-built as you are. He can’t take as much rough housing as you. Ironic huh…” Undyne paused, she had to choose her words with a touch of empathy, “Sans is strong, he’s really impressive in his fighting, but you need to make him stronger, I’ve seen you train. Sans would love to watch you do your weight training.” She paused, “Maybe, get him to join in…he needs support or…” Her words drive outwards, not quite reaching their intended destination.

“Or **what** Undyne?” Papyrus raised his voice, deepening slightly out of paranoia.

“He’s not going to survive…out on the field…Alphys said it herself. He’s smart but he needs some physical training, pump some strength into him...make let him lift some weights with you…he might enjoy the gun show?” Her voice carried disdain, but it was true. Sans was physically weak. He could bump and maybe topple over Papyrus (if he let him), but against multiple enemies, Sans was dust. “Papyrus, go talk to him, lighten his mood a bit. Maybe ask him what **he** wants. Indulge him perhaps?”

“Okay… I’ll try to make him happy, I’ve got my guitar, maybe I should sing to him...”

“Good.” The words carried some warmth, “Oh and Papyrus! Don’t be so hard on yourself, Sans clearly cares about you, you just need to start seeing beyond his cute exterior.” She laughs as they say their goodbyes, Papyrus had to make things right.

* * *

 

Papyrus opened the door, trying not to let it creak. Sans was peacefully dozing, his face and body was still blushing a vivid blue, but he looked peaceful, his face stoic. Papyrus put the food beneath his chair and held the guitar carefully in his lap, he placed one hand around the neck of the guitar, the other around the fretboard. “Sans. I love you.” The guitar strummed as quiet notes filled the room, it had been a while since Papyrus last played his guitar for someone, let alone Sans.

Sans turned in his bed, his sleeping face falling into and out of discomfort. He was breathing deeply, wheezing slightly at the height of each breath.

“Papy…” Sans had begun sleep talking, “Papy…where are you going? Who is **_he_**?” Sans’ face brightened, “Where is he taking you!?” Sans squirmed underneath the blankets, hands bunching up as drops of sweat began to slide down the side of his skull. “Papy, your face! I-It’s chipped!”

Sans voice cracked as he inhaled sharply, his soul was beginning to glow, its cyan tinge visible through the wrinkled sheets.

“Papy, why aren’t you listening to me!? Please talk to me! Don’t leave me to die here.” Sans paused to inhale, his breathing had become even more ragged. “Papy. I want you to stay with me…here…in the void…”

Papyrus was listening, he couldn’t wake up the toiling skeleton like this. He placed a hand on Sans’ now burning forehead. “It’ll be okay Sans.” Papyrus was tearing up, orange drops rolling from his chin onto the guitar. “Everything will be okay,” He leaned in and kissed Sans’ neon blue brow with a clink, “ _I promise_ …”

“Papy. If this is it for us…” Sans was crying in his sleep; his slumber had turned into a night terror, “I love you…”

“Sans!” Papyrus sat on the chair, a breaking monster, the room had gone silent again.

“I love you too…”

Papyrus stood up and pushed the chair away, he sat on the soft shag carpet, legs crossed, leaning against the bed. He began playing once again as the room began to darken as storm clouds rolled in. He couldn’t watch Sans writhe in pain anymore.

Papyrus’ fingers began to glow orange as the room filled with the gentle mellifluous strums that honeyed the atmosphere.

Papyrus was crying; awake. Sans was crying; asleep. Both brothers were drowning in each other’s sorrows.

“PAPY! DON’T GO! I NEED YOU! I NEED TO KEEP YOU HAPPY!”

Papyrus began playing louder, smothering cries of pain with his own shaking voice, breaking into a smorzando.

_“You are my sunshine.”_

Sans screamed louder; crying.

_“My only sunshine.”_

Sans began to glow brighter; luminescing.

_“You m-make me h-happy…”_

Sans began to hyperventilate; panicking.

_“w-when skies are grey…”_

Sans choked on his tears; regressing.

_“you n-never know, dear…”_

Sans went silent.

_“how much I l-l-love you…”_

Nothing mattered now.

_“please don’t take, m-my sans-shine, away……….”_

Papyrus stopped playing. Everything felt and went black. And everything went and felt detached. Nothing was real here. The air was heavy, it felt asphyxiating, suffocating him as he sat losing determination in the bleakness that now saturated everything in its dark omnipresence.

Papyrus put his guitar down and sat, knees to his chest. Absolutely nothing was glowing now except his tears, slowly burning down his face and into his hoodie, which was now tightened around his head. He was cracking, his soul was oozing lightly; this was heartache.

“PAPYRUS PLEASE NEVER LEAVE ME!!!”

Papyrus turned around to see Sans sitting upright, his eyes wide and screaming blue. Small wisps of blue steam flowed out of both his eyes and mouth between painful gasps of air. He was shaking uncontrollably, head spinning; searching for something to focus and ground himself on. Papyrus grabbed him and pulled him into a tight hug, it was all he could do as they both cried louder.

“Sans I’m sorry. Sorry for being such a shit brother for you.” Papyrus hugged even harder as Sans wrapped himself tightly around the larger skeleton, small hands barely able to encompass his ribcage, “I love you Sans. I’m never going to leave you. I’m gonna help you become the royal guard’s fiercest warrior. I-I promise. I will do this for you.”

Sans kept hugging Papyrus, it was all he could do as tears continued rolling down his face. His breathing began to regulate as he looked at his brother’s tired crying eyes.

“Papy. I’m sorry I couldn’t be strong for you. I’m weak aren’t I?” Sans held back coughing sobs, Papyrus pulled Sans’ forehead to his, their close embrace a chance to finally talk. They sit on the bed, right next to one another.

“Sans. Undyne spoke to me today, she wants me to help you train, make you stronger. You can become strong like your big bro right. You can help me lift weights. You can become the Fantastic Sans!” Papyrus could barely speak, gagging on his own tears as the desperate words spilled out.

“Papy…you don’t have to do this for me…it’d be a waste of time…” Sans started to blush blue at the thought of seeing his brother working out, “It’s not like I would benefit from it…” Papyrus turned his head to Sans, his orange eyes carried seriousness amongst the tears.

“Sans, I love you,” Papyrus rubs Sans’ leg gently, “I _really_ love you. You’re worth my time. You remember the assassination, you fucking owned me then!”

“I-I guess I did huh?” Sans wipes his face with his shirt as Papyrus starts tickling Sans’ belly, causing him to giggle as fingers explore his neck and ribs. “Papy stahp it! I can’t b-breathe…” Sans is laughing hysterically as he begs Papyrus to stop his tickle assault.

“Sans, you know you like it, ever since the assassination you’ve been more open about us.” Sans blushes even more, he covers his face as Papyrus stops tickling and massages his brother’s shoulders. “And Sans, I wanna know the question you had for me before.”

“O-OH… that? I was going to ask what you’re favourite food was…but I sorta knew you’d say honey Papy.”

Papyrus noogies Sans gently, “I do love honey,” Papyrus chuckles softly, “but I love you more my cute little bro.” Sans looks up nervously, the butterflies in his stomach are picking up wind, he swallows and takes a breath.

_“All you gotta do is ask him, Papy trusts you enough, he’ll let you do this. He loves you…”_

Sans twiddles his thumbs once more, his face and phalanges glowed blue. He engages with Papyrus simmering orange eyes with his big blue eyes, “Papyrus, c-can you help me with something?” Sans shakily places one hand over his crotch as a light blue glow emanates from it. “Papy, h-h-h-how do you make…your cock appear so…um…v-vividly…?”

Papyrus dropped his guitar onto the floor, such a question was odd to hear out of Sans mouth, it pierced the air and broke the tension into unequal portions fear, shame, lust and excitement.

“I’ve watched you a bunch of times,” The small skeleton flushed at admitting his voyeuristic habits, “and every time your dick is so…s-so…” Sans continues to sweat and spittle as Papyrus remained awestruck, “So…so hot…and it looks really big and hard…”

“Sans…d-do you want me to show you how to…jack off?” Papyrus could barely speak let alone demonstrate such a lewd concept, his face flushed as he nervously eyed Sans’ crotch, which had begun glowing blue. “Papyrus lays down on the bed with sans, both of them leaning against the headboard. Sans looks at Papyrus with a hint of frustration, he wasn’t naïve, just…inexperienced.

“I know how to…m-masturbate, sort of. Remember my assassination of you…” Papyrus’ laughs nervously as he recalls the blowjob and Sans’ expert tongue, he was in heat at the time, his senses were nullified by pure unabashed desire. “I literally killed you with my…manoeuvres…” Sans couldn’t bring himself to curse or talk even remotely dirty, “I want to see how to conjure something as incredible as your m-member.” Papyrus was flushing even more brightly, his erection was beginning to take shape as Sans praised his manhood; stroking his ego.

“Papy…I want to watch you. And…maybe one day…we can do it…together…like in…Undyne’s…a-anime…” Sans shook as he undid his neckerchief to relieve his closing dry throat. Papyrus was breathing heavily, he was excited. They were both getting what they finally wanted, what they had been craving for such a long time.

Papyrus looked at Sans through the darkness, the only things bathing their bodies in light were their eyes, souls, and now, their pants.

_“Don’t fuck this up Pap. Stay in control. Just show him your dick and tell him how to make his…I CAN’T FUCKING DO THIS…”_

With shaking hands Papyrus pulled his shorts down his legs and removed his hoodie, he didn’t have his black tank on, it was still torn from the knife.

Sans mimicked the disrobing in a similar fashion. Papyrus put his jumper beneath his legs, Sans put his shirt beneath his. They were fully naked.

“Ready Sans?” Papyrus held up a walled smile, masking his looming anxiousness, “If I’m going too fast just tell me. We’ve got all day…and…you’ve seen how long I can go for huh…” Sans nods eagerly as Papyrus gestured towards his pelvis.

“Okay. Erm…so when we skeletons get turned on, our pelvises glow, so every time I see you glowing down there…I‘ve sort of known you’re all hot and bothered…”

Sans looked up in disbelief and how obvious his arousal was to the public eye, especially his own big bro. He looked at his own crotch, its glow was much more intense than Papyrus’, Sans’ soul was also glowing: A monster’s soul is extremely sensitive to touch, even squeezing it can induce explosive results to the recipient’s nerves causing the soul to ooze. Upon climax the soul gushes outwards in a spray of hot wet liquid with a viscosity akin to that of blood; thicker than water but thinner than honey. If the user is able to physically connect two souls as both parties climax simultaneously, something incredible would certainly occur…

“Papy, I’m ready for the next step.” Sans twitched, he lacked the autonomy to manifest his energy, as well as ask the questions he wanted to know about pleasure and orgasm, “Um…” Sans’ eyes darted from Papyrus to his crotch repeatedly.

“Papy, can y-you, be gentle with me…y-you go really f-f-fast…and you’ve got such rough hands…” Sans shrunk, slinking onto his back.

“Sans, this is all you now, I will do everything you want me to, _anything…_ ” Papyrus cracked his neck and fingers, little whimpers escaped Sans mouth as he felt himself grow hotter. “Okay Sans, focus your energy onto someone or something, displace the energy from your brain to your pelvis, and just _let it happen_. It feels unconscious, like falling asleep.” Papyrus pat Sans’ gently on the shoulder, “Have a go bro. Think about something really fucking hot.”

Sans closed his eyes in thought.

Papyrus was bent over a pillow, furiously grinding against it, his thick orange cock slid over the cum soaked fabric. He fucked it harder, moaning as his soul glowed and oozed, squirting orange goo everywhere. One hand was holding the pillow, the other furiously rubbing his spine like a pole, up and down, making it glow with ecstatic pleasure. Papyrus bucked, his cock shooting some pre forward, spraying from the tip. “Ugnhhhh…f-fuck!” Papyrus wrapped one hand around his large girth, his hips riveted forwards into his hand, the sounds of his deep rugged breaths now also accompanied by sharp roars from his fervid throat.

**“FUCK ME SANS! FUCK ME LIKE THE SLUT I AM!”**

Papyrus’ hand worked his length over and over, increasing in speed. Hot, wet cum leaked out of the tip like a tap before gushing out, shooting a few feet into the air, Papyrus sat up and aimed his enormous cock at his face, shooting himself with his magnificent seed.

**“SANS PLEASE! CUM ALL OVER ME!”**

One hand continued pumping his girth, the other rubbed his spine faster and faster, his soul was shooting out honey coloured love. His skull was covered in his marmalade jizz, it dripped from his eye sockets and chin, he had a weak smile on his face, and his eyes rolled back in utter bliss.

**“UUGH FUCK…SANS THIS FEELS SO GOOD…NNNNNGGG…OOHHH…Ohhhhhhhh…”**

Upon opening his eyes, a blue erection had taken shape, it was glowing gently. It had to be just over five inches in length, its circumference however, at least seven inches. Sans reached down to feel it and wrapped his small fingers around the tip, his thumb rubbed in small circles. The newfound pleasure made him shiver and coo, his neck arching back. Papyrus watched in wait, his own arousal growing watching Sans’ own innocence burn up before his eyes.

Sans burst into moans of pleasure, Papyrus’ stomach turned hearing the loud blares of muffled glee. Sans collected a drop of his blue glow in the dark seed. He brought his finger to his mouth, a thin, slippery neon blue tongue wrapped its way around his finger before pulling it into his maw. He sucked it clean off before going back to his risqué work.

“Papy…” Sans turns to face Papyrus, his face was covered in thirst for more, he needed more, “Show me what to do next, maybe you could…demonstrate…please..?”

Demonstrating wouldn’t be easy for Papyrus. Seeing the familiar naïve way Sans sucked his finger was hard enough on the guy. Now he had to show him how to pleasure himself; teacher to student. Papyrus’ eye sockets widened in fear, Sans’ grew in anticipation. The soft beating of Papyrus’ soul could be heard as it began watering more and more, his jumper had started to become wet.

Papyrus focused his energy as his dick took form, it materialised quickly; he’d fine-tuned his method of phallic retrieval. His member was much larger than Sans’, the shaft had to be at least ten inches long. It was so fucking thick too, nine inches around his total girth. The entire length throbbed as Papyrus flexed it, making it stand up rock hard; leaking cum at full mast. Sans watched Papyrus’ strained face as he began moaning without even touching himself, his cock lowered and raised over and over, he tensed the muscles, forcing cum to leak from its tip. His soul began to squirt as his hands explored his spine and ribs.

Ragged breaths filled the air. Papyrus gasped violently as he grabbed his cock with both hands now firmly clasped around its width. He slowly slides his phalanges up and down the entire length, bulbous orange tip to thick beer can base. Deep grunts filled the air, his rough incoherent verses of ecstasy making Sans sweat, the demonstration has finally begun with the vocalising of loud cursing and heavy panting.

Sans placed his hands around his member and like his brother, tensed it, squeezed it, and stroked it.

“Ugghhh…Papy…a-a-am I doing it right?!” A loud moan answered his question, Papyrus was jutting his pelvis up and then letting gravity pull him back down as he bounced rhythmically on the bed, his cock sliding between his stationary hands. “Papy…uugghhh…nnnngghh…t-t-this feels…incredible…” Sans arched his spine as his soul glowed brighter with each thrust, it oozed a cerulean fluid which sprayed outwards with every moan. The two brother’s moaned louder in unison as soul spray shot onto them.

Papyrus sat up straight to face Sans, leaving his erection to throb in syncopation with his beating soul.

“Sans…you’re doing everything….nnggghhh….p-perfectly. Sans you look so hot and cute and sexy like that. Come sit on Papy’s lap…I want to…show you…something…really, **really** hot…”

Everything became a blur for Sans as he was hoisted up by Papyrus. The older skeleton sat the edge of the bed and placed Sans on his pelvis, their dicks were now pressed against hard each other. Everything felt thick and thin, the air just didn’t quite meld right. Sans watched nervously, blue drool slowly dripping down his face as Papyrus looked right into his blue eyes. Papyrus had such soft, sleepy eyes, which weren’t as livid as they used to be. They glowed gently, an air-tight layer of sorrow glazed over them like a persistent gel.

Their souls sat at the edge of their ribcages, dripping onto their blue and orange stained bones and pulling each other together like magnets.

“Okay Sans, I’m gonna show you my favourite trick, you can join in if you want.”

Papyrus smirked as he crushed both their cocks in one hand and pumped them in unison, cum was now leaking over both shafts, orange and blue seed mixing into a purple colour, it felt hot and cold and almost electric in the way it trickled down their cocks and fingers.

“Papy! Uhhggghhh….NYYHHHAA!!!” Sans was already on the verge of snapping, his soul shot out a burst of glowing essence as Papyrus cursed loudly, reverberating and echoing into what was once silence. Sans placed his hand over his brother’s as they stoked together, even harder and faster. Papyrus was flushed deeply as Sans began to take over. “Papy, let me finish this for you, let Sans make Papy proud!”

Both skeletons began to glow together: souls, faces and cocks all alight and dripping in pleasure. Sans stroked even faster, guiding Papyrus’ hand up and down to his desires, squeezing their cocks together. Sans began approaching climax, his quiet voice continued to moan and beg for release, it increased in volume and frequency as Sans started to make Papyrus yearn for his sexual explosion.

“FfffffFUCK!!” Papyrus jerked his entire body as his cock shot a blast of cum into the air as more spurts of love shot up and onto either brother. His eyes were lulled upwards as his mouth drooped into orgasm. His soul burst as orange honey sprayed everywhere, coating both skeletons in the gooey material.

“Sans…f-fuck…does-s this-s f-f-feel-l-l good?” He kept pumping both cocks, Sans explored their shafts, their smoothness, their curvature, their throbbing veins and their leaking, cumming slits. Sans couldn’t control his breathing, another gasp escaped his throat, this one was louder and less in control. Tears of fatigue from the adrenaline began to conjure from his eye sockets.

“Papy…” Sans’ soul began glowing brighter, “oh Papy…PAPY!” Papyrus began to pump faster as Sans let go of their cocks and began stroking his spine, his soul spewed again, blue soul cum coating his ribs, “PAPY…HHH…NYAHHHH…PAPY…HARDER!!!”

Sans tilted his head back, his hand was rubbing furiously along his spine, every crevice and vertebrae was being pleasured. Sans’ neck arched further back as he succumbed to pleasure. Papyrus was approaching his second orgasm, it felt much larger and louder and rough. Papyrus grabbed both dicks and crossed them over in an X-shape to face the opposite skeleton. Papyrus rubbed beneath the head of Sans’ cock, massaging slowly, pressing one length against the other.

“Sans…bro…you ready…because I think this lecture is almost over…”

They were breathless, panting loudly and roughly, there was no going back.

Sans rubbed himself harder, moaning Papyrus’ name over and over. His soul began to shake and glow vibrant shades of blue.

Papyrus leaned into Sans ear.

“I fucking love you Sans You’re so god damn fucking incredible.”

“P-Pap-Papy” he couldn’t speak, this was all pleasure now, “I l-love you too…”

This was it.

 “SANS I’M GONNA CUM!!!”

Papyrus roared and squirted his love over Sans’ body, pleasure bathing his bones, Sans was bathed in Papyrus’ copious fluid as his cock discharged. Their hips thrust backwards and forwards gaining final notes of friction as Sans shot his blue load onto his brother’s face, drenching him completely in seed.

They sat in silence as Sans rested his head against Papyrus’ ribcage, their dicks still oozing and leaking sticky goodness. They were covered in soul cum, the blue and orange substance was different to their cumshots, it felt more honey-like but it still dribbled fluidly.

Thirty minutes passed before either skeleton uttered another word.

“Papy. T-thank you. For everything.” Sans held his brother’s hand and squeezed it gently, “I can’t wait to start training with you, lifting those weights seems fun…” Sans shines a smile at Papyrus, “We can train together!” The small skeleton is shaking in delight.

“Yeah Sans, I can’t wait!” Papyrus was glad to see Sans beaming again.

“Oh and Papy.” Sans pauses, “I need to repay you for all this…you like honey and cats…maybe something with those…”

Papyrus looks at Sans and shudders.

* * *

 

 

Sans continued to drip at the doorway, the lace of his outfit was layered in honey. A small collar was around his neck, little cat ears twitched nervously.   

“Papy! Do you like my clothes?

Sans twirled around, honey continued to slime onto the carpet.

**Papyrus was finally in heat.**

**Notes for the Chapter:**

> SORRY THIS CHAPTER TOOK SO LONG IT IS A VERY LONG CHAPTER!!!
> 
> I have been travelling and haven't been at home for over 2 weeks so I write when and where I can. Chapter 3 was a writing test on angst and slight inexperience of one party in the relationship.
> 
> Chapter 4 will be all about the present scene. HONEY. TOOTHBRUSHES. Sans being a maid with cat ears (XD), and lots of rough, hard fucking and so much smut. I'm talking I'm gonna be going to hell for this.
> 
> I WILL BECOME SATAN IS WHAT I'M ELUDING TO...


	4. Turn Up the Heat

**Summary for the Chapter:**

> Thinking about it the whole situation was absurd, but here they were, in heat: Sans drenched in honey, torturing poor Papyrus, cat ears and tail glowing their gentle blue. His maid costume wasn't helping either. 
> 
> In a game of who dominates who, one brother obviously comes out on top, but the aftermath is something I don't think anyone is going to expect.
> 
> HEHEH.

“Is something distracting you Papy?”

What stood before Papyrus was sopping wet and covered in honey, he looked and smelt so sweet; innocence was such a fragile facade. Sans’ blue maid outfit bore low to the knees with pastel coloured frills that swayed with his hips. Little blue cat ears and a long swirling tail accompanied the erotic ensemble. Cyan irises looked at Papyrus, their natural purity a temptation once forbidden but now ripe to pick.

Nervous shuffling made the bed creak under Papyrus’ weight as Sans slowly stepped towards him, leaving a small trail of honey on the floor. Papyrus could feel the heat begin to overcome him, his pelvis was beginning to burn more intensely as his hands and face burnt up as faint orange vapour trails radiated from his fingertips.

“N-no it’s n-n-nothing Sans! I-I’m fine!”

Sans stepped closer as he began to undo his apron with a hand, the other one politely stowed behind his back. His slippers dragged along the carpet slowly. He was in a trance, hypnotised by what was now overbearing primal urges. Papyrus squirmed in discomfort, he had never been with Sans during a heat, he always hid himself away. Sans would often separate himself and hide, trying to avoid his brother whilst in heat; to prevent this exact scenario from coming to fruition. Papyrus slammed one hand against his pelvis to try and hide an overly apparent erection, he felt a wet patch and saw a glowing stain that ran down his leg as his dick continued to painfully leak its orange pre.

Sans asked again.

“Papy, are you one-hundred percent sure you don’t need any help from me? I want to help my master after all.”

A direct stabbing pain flew across Papyrus’ body upon absorbing the words, he bucked into his hand, letting out a supressed groan of pleasure at the grinding feeling. Sans got closer, there was no turning back now. Sans wasn’t even making any physical advances, it was odd seeing him carry himself so fluidly, yet every movement was calculated, planned, previewed and executed. He sat next to Papyrus on the bed, scooting even closer to his hips.

Papyrus was flustered, a ruined mess, sweating was the first thing on the laundry list of anxieties and physical maladies that made him sexually overt. The two brother’s had stark contrasts; emotions contradicted their usual personifications. Papyrus, usually calm and suave, was now wheezing and had his hoodie nonchalantly yet worryingly tightened around his head. His hands twitched and clamped into fists that were just as sweaty as his forehead, and which like the rest of his face, was tangerine in colour. His words lost their cockiness, being replaced with absentminded drivel. His legs were closed together, erection wedged between them, holding it from springing up and ripping its way into the open air. The heat made him emotionally neurotic, high strung and so very anxious, yet, once he was in position, there was no braking his sexual frustrations.

A calm hand rested on Papyrus’ leg, yet a cold hand, the small skeleton had placed a bottle of honey behind Papyrus. When Sans was in heat, he became maniacal. Yes, he may have carried the physical symptoms and visual cues of heat, his body was glowing just like his brother’s, yet, his composure condensed and he closed up, preferring to become reserved and inward. He had two settings: lustful and horny, and often the switch could become broken and sit on one or the other for hours on end. Now, he was calm and closing in for the kill.

“S-Sans. I don’t think I n-need your h-HELP!”

Sans grabbed Papyrus by the shorts and rolled his chubby body over onto his thighs. Sans was on his knees facing Papyrus, his tail curling into the opening between Papyrus’ thighs, he settled himself just right so that if Papyrus were to spread his legs his member would spring right into Sans’ crotch. The only challenge was getting him to crack and open up.

Sans looked at Papyrus, ears folded in a faux sadness, “But I want to help you Papy,” His tongue drooped, dripping innocuously as he leaned close to the side of Papyrus’ skull, “Let me be your little slut daddy.”

Papyrus’ eyes widened as his pupils burned and his jaw dropped. His whole body shivered at the word, it felt good, yet everything burnt so bad at. He pressed his legs together crushing Sans’ tail between them, “Papy NYA-ughhhh.” Papyrus opened his legs slightly reflexively as Sans made his next move. He grabbed the bottle of honey and squeezed it, letting some of the sweet amber ooze down the bottle and all over his hand, “Papy, I want to share some of my honey with you…” Sans poked out his tongue and drizzled a long golden strand onto it, his blue tongue still visible through the viscous syrup.

“S-S-Sans d-don’t…I can’t…”

Their mouths met as Sans’ tongue explored his brother’s lips, honey and saliva trailing down their chins. Papyrus reluctantly slid his tongue with Sans’, intertwining as the sticky mess of colours and flavours intertwined. Both skeletons closed their eyes as the kiss continued. Papyrus’ breathing became shallower as Sans’ held one hand behind the other’s skull, keeping them together. Papyrus felt along Sans’ back, reaching down and rubbing his tail, causing him to gasp as he stroked faster and faster.

The moaning got louder as Sans reached under his skirt with one hand, he _did_ have one more surprise for Papyrus, who was now leaning back. Sans leaned into the kiss, pushing his tongue to the back of Papyrus’ throat, his gag reflex began to act as Sans felt along Papyrus’ shorts for the peephole and held it open with his index and middle phalanges.

“Mmmph…Sans…I-I…”

The noises grew louder, as Sans could hear was muffled, deep grunting and broken dry moans as Papyrus continued to choke on Sans’ tongue. Sans pushed himself harder against Papyrus, he had to topple him backwards for this to work, this HAD to work. He reached his free hand onto Papyrus’ chest and pushed against him, he shuffled, he moaned, he cried, he rubbed…nothing. He still couldn’t shove him down.

_‘Time for plan B Sans…Papy won’t know what hit him…’_

Sans slid his hand into the peephole of Papyrus’ shorts, fingers spread in a ‘V’ shape into his pelvis.

“HOLY FUCK SANS!!!”

Papyrus fell back out of their kiss and onto his back, a strand of honey between their mouths broke as he landed with a squelch onto the honey covered mattress. Sans’ hand was deep in Papyrus’ shorts. Sans was smirking devilishly, purring quietly as his fangs dripped with honey. His tail lifted his skirt revealing his cyan shaft. As usual it dripped, seeping blue from its tip and it illuminated the space around it, ebbing away a dark blue mist.

“SANS?! WHAT DID YOU DO DOWN THERE!? IT FEELS…ODD…”

Papyrus was in total shock, his jaw was agape, he was panting heavily. Sans returned the question with a smirk as he opened his fingers wider. Papyrus moaned in response as the hidden hand did its work around his pelvis.

“Papy, why don’t you look for yourself..?”

_‘Shit.”_

Papyrus grabbed his waistband as Sans slowly removed his orange goo covered fingers from the peephole.

_‘Sans couldn’t have done THAT…’_

They dripped like honey as he licked the substance off of his fingers.

_‘Oh my god…’_

Papyrus looked down at his crotch, or lack thereof.

“S-SANS! W-WHAT DID YOU DO!?”

Deciding to test the waters, a nervous hand felt the lips of the newly formed vagina, he cooed as trembling digits slid in slowly, exploring and experimenting with the newfound and still very unknown territory.

“What _didn’t_ I do Papy?”

Sans looked onwards with blue innocent eyes once again, he crawled over Papyrus, more honey cascading from his body all over his brother. Sans placed his index finger on his brother’s chin and traced it down and along his figure, from his clavicle and down to his pelvis, he curled along his ischium, letting out a sly chuckle seeing Papyrus moan as he continued fingering his pussy.

“Sans…h-how did you do…uughhhh…this..?”

“Papy, I think you know exactly what I did.”

Sans grabbed Papyrus’ hand and removed it from his entrance.

“Don’t get too excited Papy,” He lifted his brother’s hand and held it above his head, “Let your little bro handle this one…”

“S-S-Sans? What are you doing!?”

A thin blue tentacle protruded outwards from behind Sans, slithering its way up and around Papyrus’ wrist and pinning his arm behind his head.

“S-Sans…w-what are you doing?”

The smaller skeleton smirked, pointed teeth glinting in the dark, his long tail reached under Papyrus’ hoodie, taking its time to tickle such sensitive ribs.

“Heh…S-Sans…heheh…please…”

Sans grabbed his brother’s free arm and held it up with the first, binding both hands tightly together with the tentacle crushing his wrists; stuck together with sweat and golden honey.

“P-p-please Sans…I…heheh…I-I…s-stop…heheh!”

Papyrus couldn’t hold himself as his hips bucked upwards and his spine outstretched, his whole body arched and ached in pleasure. Sans lifted Pap’s hoodie over his head, no tank top, it was still in repairs with Asgore who was stitching it back together. Papyrus was flat on his back, his naked body being rubbed by Sans’ fluffy tail, slightly sodden from the honey. Sans grabbed the bottle of honey and drizzled it over his brother’s ribs and coccyx, letting it drip down his tailbone as he continued to laugh. Tears began forming from the overstimulation.

“Papy,” Sans looks at Papyrus with cold eyes as he lines his dick up with Papyrus’ pelvis, “It’s my turn to make you be the slut.”

And with that Papyrus gagged on his spit, his eyes rolled back and his entire skeleton ached with broken and defeated pleasure, stirring through him like a rampant typhoon. His legs confined around Sans’ back as he pulled him and his erection fully into his body, everything was glowing amongst the two of them, their love a glowing ball of orange and blue, bathing the darkness in odd shades of green. Their souls began to ooze as Sans began thrusting in and out of his brother, hands on his shoulders, he wasn’t going to treat him gently.

“S-Sans…fuuckk!!”

Papyrus moaned with each of Sans’ thrusts as the smaller skeleton struggled to maintain his composure, he’d planned the whole situation out, but rehearsing the act was never the same as opening for the big debut. Moans irked and withered between the both of them as Sans withdrew his hips, pausing to breathe before slamming his length back into Papyrus, his rhythm matched his brother’s orgasmic breathing, shallow, wild and unfiltered.

Each moment felt everlasting as their souls began to glow, like usual they dripped dark shades of orange and blue, occasionally squirting outwards when a spike of pleasure riddled through either brother, often onto their faces if the pleasure was climactic.

“S-Sans…uuughhh…nnghhh…k-keep going…fuck me…”

Papyrus continued to grunt as Sans grabbed Papyrus by the hips to garner a tighter and cleaner thrust, neither skeleton could hold on as Papyrus’ walls were stretched open by Sans’ cock, his orange goo mixing with Sans’ as it leaked down onto the bed, which was slowly becoming a mixture of multi-coloured cum and honey.

The blue tail continued to explore its way around Papyrus’ ribs, coiling its way up through his body, making him beg for air as laughter mixed with tears and pleasure and frustration. The squirming continued as Sans thrusted in and out, slowly pulling his length out and pleasuring his brother’s bones before slamming himself back in, both of them moaning louder, their high and low grunts overlapping in pitch.

“Papy…mmphh…you look so cute like that…underneath is so much nicer isn’t it..?”

Papyrus’ eye burnt at the infatuating backhanded compliment.

“I’m gonna make you mine Papy…I’ve finally got you where I want you…”

Sans smirked as he grabbed the honey bottle and squeezed it over his own face, his eyes vapouring a blue mist as honey slimed down his face and over his mouth, onto his ribs, onto his pelvis, along his legs, down to his feet, and all over Papyrus.

“S-Sans…”

He could barely speak as Sans pulled his length out, it was covered in orange love, the entrance leaked blue cum as Sans returned his phalanges into Papyrus’ vagina. One finger slid in and out as Papyrus’ walls contracted around it. His bony digit continued to explore as a second finger accompanied the first.

“S-Sans please…”

Unfortunately Sans didn’t stop, a third finger was shoved into him sharply, a pained yell rang through the room as a squirt of orange erupted form both his soul and entrance, splattering his ribs orange as well as wetting Sans’ arm. He ran a finger along his hand, collecting a small mixture of the blue and orange soul goo, as well as some honey and orange cum. He brought it to his mouth as his blue tongue inquisitively samples the erotic concoction.

“Sans…”

His ears perked up and flattened as his face broadened into a maniacal grin, his blue eyes began to lose their initial innocence as he pawed his way further up his brother’s body, keeping his fingers deep in Papyrus’ privates. Fear came to Papyrus next as Sans brought the goo covered hand towards his face, the sticky mixture was edging towards his mouth.

“S-Sans I don’t want to lick your h-HAN-!“

Before he could say another word Sans shoved his finger into Papyrus’ mouth. His entire body shook as one hand explored his mouth and the other slid in and out of his vagina, a single digit rubbing his clit before joining the other two, opening his hole wide, pressing against his flesh.

“What do we taste like Papy? I think you taste so sweet…”

He pressed a fourth finger deep, muffled curses got louder, accompanied by moans. Sans shoved further in causing Papyrus to gag uncomfortably. He shuffled further back as Sans grabbed his tongue and held him in place, fingers wrapping tightly around the slippery appendage.

“S-Sans…”

“Papy…I said do we taste nice..?”

“Sans…”

Papyrus squirmed as he looked at Sans once more, honey covered and now not so innocent, his dress was soaked and his ears and tail had flecks of orange goo on them. Sans pulled his hand out Papyrus’ mouth, a trail of saliva stringing its way as Sans began to turn to face the other way. As he rotated his body he twisted his fingers within Papyrus, making him groan once again, the poor skeleton had little to no control over his little brother’s evil manoeuvres.

“F-Fuuuuck…S-Sans…”

Papyrus grunted as Sans turned his body so that they were in a sixty-nine position. His blue erection sat pointed towards Papyrus’ mouth as he dipped his tongue into Papyrus’ vagina, dipping and exploring slowly as he began eating him out.

“S-Sans…aaah…fuck…t-that feels…g-good…”

He opened Papyrus wide with both hands, he shoved his face in deeper. The combination of rough, soft and wet stimuli made Papyrus moan louder as his own hands struggled to free themselves from Sans tentacles. Things only got louder as Sans thrusted his hips backwards, giving Papyrus no time to open his mouth up. His dick slid up against his nose as Papyrus brought it into his mouth with his tongue and began to gag on its length, blue cum trickled down his mouth, his whole face was a mixture of fluids at this point.

“I told you that you’d like it.”

Sans removed his tongue and shoved his whole hand into Papyrus instead, thrusting in and out as he chokes on Sans’ cock, his spine arched as his soul squirted upwards, all over Sans’ blue dress and tail, “You told me to trust you Papy, and I do. You should trust me too.”

Papyrus looked back at Sans nervously, he trusted him. At least he thought he did. Sans trusted him, there was no doubt about it; unwavering innocent trust, perhaps leaning on guileless devotion. Sans stood by his brother, even now while being face-fucked.

_“I really trust you Sans.”_

His little blue face lit up with a smile as he dematerialised his tail and ears. The tentacles loosened around Papyrus’ wrists leaving blue goo markings as they slithered away. He slid his hand further into Papyrus, testing the depths of his ectoparts, making him squirm continuously as the dressed skeleton fisted even harder, plunging his fist in and out over and over again.

“Fffffuuuu…Sans…oh FUCK…”

The moans broke into even louder screams of pleasure as Sans joined in panting in and out of rhythm with Papyrus, the two of them gradually getting louder as their souls glowed brighter, dripping onto their bones and seeping into the mattress.

“S-SANS!!! H-HARDER…I’M GONNA…” Papyrus thrusts his crotch upwards into Sans’ fist, orange spraying up and around his arm. It sprayed all over his face, his arm acting like a cork in the champagne bottle.

“P-PAPY…Y-you’re making a mess…mmmmphh…”

Papyrus coiled his tongue around Sans’ member as he wrapped both free hands around it, sucking it harder as well as thrusting it into his mouth pulling Sans back with it; his teeth glided along its lubricated surface, making the smaller skeleton moan in response. It leaked blue into his mouth as Sans continued to slide his wet fingers in and out of his brother, the digits scraping against his overstimulated walls. Papyrus gasped and gaged as Sans member filled his mouth with pre.

“Papy…mmpphh…I’m…heh…ugghhh…”

His small moans get louder and louder as Papyrus took San’s entire length into his mouth. Tasting his pre as well as all the other fluids left on his bones.

“Mmuugggh…Pap…Pap…uughhh Papy…PAPY…PAPY!”

Sans yelped as his body collapsed upon orgasm his hand falling limp as his body slumps onto Papyrus’ legs.

“Hey Sans…do you still trust me?”

“What what are you sayi-!!!”

Sans was still laying on his stomach as Papyrus grabbed his legs, the next blurry seconds involved his legs being thrown upwards as he flipped over onto his back, his body doing a 180 degree turn. During the motion he was still in mid orgasm, Papyrus could see the fear on Sans’ face as his brain was processing everything, he came in the arcing motion, blue spraying up into the air before landing all over both of them.

 “Papy! W-what was t-that for!?”

“I can’t let you have all the fun today Sans…”

The room feel silent save for their rapid breathing, Sans was physically spent, his body couldn’t handle much more. His clothing was tattered as Papyrus cradled his wet body and removed the dress from him, they were both bare, wet and dripping in their blue and orange love.

“Let’s get you cleaned up Sans…”

* * *

 

The bathroom door opened with a creak as a fluorescent light hummed and switched on, filling the black room with artificial and dusted light. Papyrus placed Sans on the red leather stool, he had fallen asleep; his face and fingers still glowed amongst the rest of his burning body. But Papyrus wasn’t any better, his broad rib cage was splattered with cum, his pelvis was still burning like his face, blushing a bright orange. Both of them were still sticky with honey.

Small orange tentacles wrapped around Sans’ body, the quiet act the first of many in the devious intricacies in revenge.

Papyrus grabbed an electric toothbrush as well as some other brushes of assorted bristle size and thickness, he didn’t need toothpaste however; some hot soapy water would suffice, scented with lavender and other floral notes.

“Sans…wake up…”

The small skeleton bubbled in his sleep, perking up at the sound of his name.

“W-what is it Papy? Is it t-time for my…” he yawned as his face drooped back down, “m-my bath..?”

Papyrus smirked as he clicking the toothbrush on, the electric hum filing the room clinically, like a surgical theatre moments before the big operation.

“Heh…you could say that…”

He brought the brush to Sans mouth, before lowering his arm towards the centre of his clavicle, he brought it close to each of his ribs, but this was part of the waiting game…

“W-wait!?” Sans began to struggle but to no avail, his arms and legs were bound together and to the chair, “What are you doing Papy!?”

Papyrus’ eyes shut off into black for a split second, they looked familiar, experimental and fairly dead. He was getting ready for his kill. He opened his mouth into a smile, exhaling a chuckle.

_“You have no idea, do you Sans…oh but this will be fun…for the both of us…”_

* * *

BONUS LINKS TO SOME COOL FANART!!! (LINKS 1 AND 4 ARE SFW, LINKS 2 AND 3 ARE NAUGHTY SEXY NSFW PICS)

<http://sansapapyrus.tumblr.com/post/138580374005/sanspar-doodles-a-bunch-of-scene-from-a-story>

<http://sansapapyrus.tumblr.com/post/138465357480/random-doodles-the-lovely-mizzyscribbles-drew-a>

<http://sansapapyrus.tumblr.com/post/137537748880/more-fanart-for-burning-together-nyeh>

<http://sansapapyrus.tumblr.com/post/137470715880/mizzyscribbles-fanart-of-chapter-3-of-burning>

 

**Notes for the Chapter:**

> OOOOOOOOOOOOOOOOOMMMMMMMMMMMMMMGGGGGGGGGGGGGGG
> 
> I am so happy to have this chapter up because my year has become very very busy and the times between updates is going to increase very much between now and chapter 5 and 6. I hope you guys really enjoyed this section of the fic and don't forget, the final chapter is gonna have some special fusion fun times with the big bara skele we call comic papyrus!
> 
> ((Don't forget to leave some kudos if you liked this fic and leave some feedback in the comments, as a newbie to the fic writing world any writing tips or general comments would be much appreciated!!! ^_^))


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